Pulverizer mill



H. v R. CARR 1,833,560

I PULVERIZER MILL Filed Feb. 10, 1930 Patented Nov. 24, 1931 PATENT OFFICE HUGH R. CARR, OF CHICAGO, ILLINOIS PULVERIZER MILL Application filed February 10, 1930. Serial No. 427,304.

The object'of this invention is to provide a simple roller type of mill for finely pulverizing coal, etc. In the drawings annexed I Fig. 1 is a vertical sectional view taken on the zigzag line indicated on Fig. 2; I

Fig. 2 is a plan view of the roll system with "the top plate removed.

' Referring to the drawings annexed by refcreme-characters, 5 designates a vertical shaft which may be driven by any sultable mechanism from 'below,,a part of one of the gears being shown at 6. This shaft extends up through the'bottom plate 7 of the'apparatus and has keyed to itsupper end a pa r of plates-8 and 9 spaced far enough apart to receive a series of rolls, hereinafter described; 'As'a' convenient means of spacing these plates apart, I employ a collar 10. Supported in theframe'work 11 of the apparates is a. grinding rin 12 which lies coincident with the space between the plates 8 and 9. The materialto be coinminuted is introduced into the apparatus [through a spoutl3 which delivers the material into the 'space'between the disks through an annular "seriesfof'openings 14 formed in the upper disk."- f

Secured to the'u-nder face of the lower disk 9 is a series of radial plow-plates 15 which 'workin an annular space'formed' above the bottom plate 7 bythe frame 11. Inth'e'wall -11 is formeda series of openings or louvers -16." Supported freely between the two disks and resting entirely upon the lower disk are two series of rolls, the outer series being des ignated bythe numeral 17 and the inner series by thenumeral 18. These'rolls have fiat peripheries and they areaxleless, their sole supportibeing the lower disk 9. 7 These disks 1 rest freely upon the lower roll and, therefore,

when the disks are rotated through the medium oftheshaft 5they are subjected to a clan trifu gal; action: The outer seriesof rolls 17 bear and roll against the inner face of the grindingwing 12, while the inner series of rolls 18 have their flat peripheries in contact with the fiat peripheries of the aforesaid outer'rolls and. are'th'erefore rotated thereby. The outer. rolls are of equal weight and size,

and the inner rolls are desirably smaller in diameter but are of equal weight and size.

In operation, the rolls will have a planetary action in that they will be bodily moved around the center of the shaft by means of the lower disk, which they gravitationally engage with sufficient friction to thus bodily move them, and also rotate on their respective axes. The outer rolls are rotated on axes by engagement with the grinding-ring 12, and these outer rolls in turn frictionally drive the inner rolls. By properly proportioning the inner and outer sets of rolls, it will be seen that one of the inner rolls will project partly into the space between the adjacent pair of outer rolls and will remain in contact therewith during the rotation of the shaft. In this way, not only the outer set of rolls, but the inher set of rolls also will be automatically kept properly spaced with reference to each other. The material fed through the upper disk 8 will first be ground between the contacting flat faces of the two sets of rolls and will then be delivered off the outer edge of the lower disk 9. The plows 15 will be so shaped as to I throw the powdered material up into the spaces between the outer rolls so that it will be caught between the peripheries of said rolls and the grinding-ring 12 and will be thereby further ground. By properly adjusting the feed of the material with respect to the grinding capacity of the apparatus, the material will be ground to a fine powder. During the operation of the apparatus, air is r drawn upwardly through the apparatus, through a cylindrical housing 19 mounted on top of the structure wall 11 and this air will be drawn in through the louvers 16 and the surrounding conduit 20. The air will pick up the material ground to a sufficient fineness to be carried by air and this dust will be delivered out through the top of the housing 9 to any suitable source of collection or use. The manner in which the dust-laden air is disposed of is not illustrated, as it forms no part of this invention. Neither is the conduit 20 or gearing 6 shown fully, as they form no partof this invention. The gearing and the lower part of the shaft 5 will be suitably housed;

I show part of this housing at'21. i

V It is important that the outer rolls 1? shall be spaced apart in order that the plows shall be capable of throwingup the partly ground material into position between the wheellrto be" re-ground against the inner face ofjring 12. It, is also important that the proportions of the parts and the number of i 10 the rolls 17 shall be such that when all the rolls are acted on by centrifugal force toan equal extent (which of course wlll be the case,

since they are all supported freelybetween the discs 8 and 9) the inner setof rolls 18 shall be prevented from being thrown'out against" the ring 12 and instead shall bepressed against the-adjacent surfaces of. the rolls, l7 soas to have grindingcontact, therewith and be rotated thereby. It is also important that th discs 8 and 9, and particularlylthe lower disc 9, shall have their outer edges terminate short of the ring 12, so that there/shall be provided'an annular space up into which'the plows maythrow thepartl'y groundmaterial in thema'nnerabove set forth. i i I have-illustrated, and I preferto. use, rollelements having flatjperipheries in rolling contact, as that form of rolling element is the' most efiicient in reducing the materialto dust form, but it will be understood that my invention is not restricted to this; form of rolling element, other forms. such as oval or spherical 'mayl be used with adyantage for some purposes. v

i WhatI claim as new is: i

- 1;, In a pulverizingf apparatus, .a frame carrying a grinding-ring facing inwardly 'andhav-ing means. for providing a supply of air thereunder, a rotatable shaft centrally arranged with respect to said ring andcarryi-ng-a pair of separated disks rotatable with r the shaft; means for feeding material "freely on the lower disk so as tohave not only fabody rotation but also an axial rotation; 2. 7111 a' pulverizing apparatus, a frame 5 fcarryingga grinding-ringfacing inwardly,

through the upper disk, and a system of grinding elements arranged betweenthe disks embodylngan outer set of rolls having fiat peripheries working against the face: of the "aforesaid grinding-ring and an inner set of rolls haying their flat peripheries rolling aga nst the per pheries of the aforesaidouter set of rolls, all ofthese'rolls being supported a rotate leshaft centrally arranged with re spectto said ring and carrying a pair of separate-d disks, rotatable fwith the shaft,

means for feeding material into the space between the disks; and a system of rolling grinding elements arrangedbetween the disks embodying an outer set of-roiling elements having rolling contact against the face of the aforesaid grinding-ring and aninner 7 set of rolling elements having-rolling contact aga nst the peripheries of the aforesaid. outer set of rolling elements, all these elementsbeing supported freely on said lower disk so as to have not only a body rotation but also an axial rotation and be held in rolling contact by centrifugal force.

3. In a pulverizing apparatus, a frame carrying a grindingnc'ingfacing inwardly,

a rotatable shaft centrally arranged with respect tosaid ring and carrying a pair of separated disks rotatable with the shaft, means for feeding material into the space between the disks, and a system of grinding elements arranged between the disks embodying an outer set of rolls, having flat peripheries working against the'face of the aforesaid grinding-ring and an inner set of rolls; havingtlieir'fiat peripheries roll againstwthe; peripheriesof the'afo'resaid outer set of rolls, all of'these rollsv being supported freely on thelower. disk so, as. to liatvenot'only a body rotation but alsoan-arial rotation andbe held in. place by centrifugal force.

4. In a'pulverizingapparatus, a'fra ne earrying a grinding ring facing inwardly, a rotatable shaft centrally arranged with respect:

to, said ring andc'arryingfa pair of separated disks, .means for feeding. material into the space between the disks, and asysteni of rolling'grindingelements arranged between the disks, embodying an outer "set of-rolling ele-* ments, having rolling contact against the face of the aforesaid grindingring and an inner set of rollingelementsihaving rolling .contact against t heperipheries of the aforesaid outer set of rollingelements, all these elements being supportedv freely on said'lower disk so as-to have' notjonly body rotation butalsoan'a-X ial rotation and be held in rollingcontactpby centrifugal force,; sai,d outer setof rolling elements being separated and the space between the'disks, and a system of rolling grinding elementsarranged between the disks embodying an outer set-of rolling elements having rolling contact against the face ofthe aforesaid grinding-ring and an v V. ratedd1sks,.means. for feeding material into innerset ofro'llingelements havingrolling contact againstthe peripheries of theaforesaid outer set? of rolling elements, all-these elements being supported freely 'on said lower disk so as to-have not; only a'bodyrotation but also an axial rotation and be held in rolling contact by centrifugal force, the lower one of said disks terminating short of the grinding'ring and rotating means being provi-ded below said lower disk to throw back the material for re-grinding against the face of said grinding-ring.

6. In a pulverizing apparatus, a frame carrying a grinding-ring facing inwardly, a rotatable shaft centrally arranged with respect to said ring and carrying a pair of separated disks, means for feeding material into the space between the disks, and a system of rolling grinding elements arranged between the disks embodying an outer set of rolling elements having rolling Contact against the face of the aforesaid grinding-ring and an inner set of rolling elements having rolling contact against the peripheries of the aforesaid outer set of rolling elements, all these elements being supported freely on said lower disk so as to have not only a body rotation but also an axial rotation and be held in rolling contact by centrifugal force, the spaces between the outer series of rolling elements being insuflicient to permit the inner rolling elements to pass outwardly by centrifugal force into the spaces between the outer series of rolling elements, whereby the spaces between the outer rolling elements will be maintained and all the rolling elements will have their positions maintained by centrifugal force alone, means being provided below the lower disk for continuously throwing the partly ground material upwardly into spaces between the outer rolling elements to be reground against the grinding-ring.

In testimony whereof I hereunto afiix my signature.

HUGH R. CARR. 

